air tank explosion

Cousin of mine used an old expansion tank for a pressure vessel on a school science exhibit. It scared the living hell out of me. I made him bring it to my place and we filled it with water and tested it. we also tested the safety to prove that it worked. Then I made him install a plate on the exhibit statin "Hydrostatic test 250 lbs PSI and the date" He installed a second plate "safety tested to 80 lbs PSI and the date" He received an extra award for the safety testing.
Live Steam scares me. High pressure air is the same explosive thing except at a little lower temperature.

bill
Bill

Mon Jan 30, 2006 10:47 pm

My brother was trying to make a steam powered rocket engine. He used a NOS tank put a electric heater element in it. Got as far as chaining it to a unused telephone pole in grandmas yard. He had a ball valve before the expansion cone when he relesed it the steam plume went to the top of the pole. I do not rember why but it never went past the test stage.

Does anyone rember I seems I heard some where a semi truck tire at 80 psi was equal to about a stick of dinimite. I cant quite rember though.

Billy

Mon Jan 30, 2006 11:20 pm

One of those split rims let go when you putting one together can kill you if you don't have it in a cage.

Bill

Tue Jan 31, 2006 2:39 am

When I worked at APCI, they had long, horizontal cylinders that they used to compress hydrogen fluoride into. Aside from that stuff being really nasty, it was, however, eminently compressable, and usually no great pressures were created.

Something went wrong, however, one day, and I suppose the reactor produced something other than the expected product. When the cylinders exploded, a very attractive woman in her early 30's was killed, and my car, and several others, parked 1/2 mile away, had holes punched in them from the shrapnel, not to mention most of the glass being broken. This was at 6:05 AM. In another 10 minutes, I would have been outside, opening up the plant for the arrival of day shift.

Compressed gas needs our respect, but is nothing more than a tool, in the end, and need not be feared irrationally.

On a comic side note, this story brought back several memories from that particular job, of which I will relate one:

They had a well at APCI, with some very high-powered pumps, and a reservoir that was enclosed in a gigantic rubber "bladder". The purpose of which was to keep the water supply from becoming contaminated from all of the chemicals and gasses floating around in the air.

Groundhogs found the banks of this reservoir irresistable, and would frequently burrow into them. I was asked on several occaisions to spend an extra shift trying to shoot some of the groundhogs, but was always warned not to hit the "bladder" with my shot.

One night while walking around the grounds, I saw a steady jet of water coming out of one of the groundhog holes. Occaisionally, this jet would stop, only to begin again, after launching a solid mass some 25 ft into the air.

Yup..you guessed it...the groundhogs had chewed through the bladder, and once in a while one would get stuck in the hole, until enough water pressure amassed behind him to launch him skyward.

It was quite a show, and I stayed there for some time. I showed the corpses of the groundhogs, and the newly created fountain to the health and safety manager the next morning, who did not find it nearly as amusing, as he told me the cost of replacing the bladder would exceed $35,000 (that was in 1980).

When they did replace the bladder, they buried chain link fence around the banks of the reservoir, and although I did not stay at that job through another season, I suspect that it worked well enough.

Tue Jan 31, 2006 8:21 am

explosion is not the only concern when dealing with compressed air.
i was a torpedoman in the navy. the torpedos used back then used a combination of 3000 psi air and the mixture of a fuel and water to make steam. one kind used alcohol, (yes, torpedo juice) the other used pure hydrogen peroxide. that stuff you get at the drug store is about a 3% solution so you can imagine the reaction when the pure stuff is contaminated.

anyhow, since the torpedos needed 3000 psi air it had to be piped throughout the submarine. after a stint in drydock for an engine replacement i got to see how the "yardbirds" checked the high pressure air for leaks. their procedure was to observe the build up of pressure from the adjoining compartment. when pressure reached max the compartment where the repair had been made was entered by one person with a broomstick. the broomstick was waved around in the air at the point of repair. if the broom handle didn't get sawn into by a stream of air the repair was complete. one of the yardbirds had no fingers on his left hand. seem that once he had heard an air leak near where he was working and ran his hand over the pipe to see where the air was coming from. you gotta respect that stuff.

Tue Jan 31, 2006 3:37 pm

Those things are really dangerous, makes me think a little about building one... I remember a steam engine that blew some years back.... bad

Johnny

Wed Feb 01, 2006 7:11 am

I LOVED to go to tractor shows where steam traction engines are displayed and running (Thresher's Reunion in Mt. Pleasant, Iowa is one of the BEST!).

However, if you recall just a few years ago in Ohio, at an antique tractor & engine show, a NEW owner of a steam traction engine was driving it to the show. The extreme weight of the engine was damaging the town's road, so a police officer followed the tracks to the show grounds. When he found the steam engine and its owner and he went to tell the man about his tracks...the whole steam traction engine EXPLOADED...Killing the owner, his best friend and the officer (also injured many by standers too).

Since that event...I am very leary around live steam equipment, unless I know it's been recently inspected and certified by a qualified boiler engineer.

Wed Feb 01, 2006 9:30 am

If I remeber correctly form the write ups following that, the problem wasn't maintenace, but that the operator apparently let it get low on water, and the head sheet became exposed to high heat, then water splashed up on it.

Wed Feb 01, 2006 10:57 am

John *.?-!.* cub owner wrote:If I remeber correctly form the write ups following that, the problem wasn't maintenace, but that the operator apparently let it get low on water, and the head sheet became exposed to high heat, then water splashed up on it.

John,

I have friends that were on the inspection team that probed the event. The boiler was so badly corroded they were amazed it held enough pressure to run the engine. Maintainance was a HUGE part of the problem... along with an operator with more money than brains. The boiler hadn't been inspected for many years. He owned a paving company and had already agreed to re-pave the streets he damaged.

The latent heat in a boiler has much more energy than the same pressure in an air tank.

That machine was raised far above the tree tops. I've heard, but can't confirm, that the energy contained in the boiler properly harnessed could put the machine in orbit. For anyone who isn't familiar with the 110 Case, it is a HUGE machine... more like a small locomotive than a tractor.

As a result of this fool's folly, neither of my friends can operate their steamers now.